The present invention relates to multi-purpose folding tools, and in particular to folding scissors incorporated in such tools.
Folding scissors of various types have been known for many years and have long been included in multi-purpose folding tools. In the past, most folding scissors in such multi-purpose tools have been very small, and therefore relatively ineffective.
One type of folding scissors in a multi-purpose tool is disclosed, for example, in Moser U.S. Pat. No. 696,995. In that type of tool one blade of a pair of scissors has an extended handle which is attached to pivot the entire pair of scissors into a storage slot in a knife handle. A second handle and its attached scissors blade are also stowed in the same slot, with the scissors blades and handles generally parallel with one another. A small leaf spring is typically used to urge the handles apart from each other to open the blades of such a pair of miniature scissors, and the spring is kept compressed when the scissors are in the stowed position. The spring typically used in such scissors is easily lost or bent accidentally to an inoperative condition.
East German Patent Publication 2,322,229 discloses another type of folding scissors using a long spring in a handle of a tool to move an auxiliary lever to urge a movable scissors handle toward a blade-opening position. This arrangement, however, fails to hold the main scissors handle stably fixed relative to the tool handle when the movable scissors handle and blade are urged in a blade-closing direction with respect to the main blade.
German Patent No. 145784 discloses a tool incorporating a folding handle with a pair of scissors blades which can be stowed within a multi-purpose tool handle, but such scissors include the previously mentioned type of spring or none at all.
In previously known folding scissors including a spring for opening the scissors blades, the force needed to move the blades in a closing or cutting direction has increased with continued closing movement of the blades. It is therefore desired to provide scissors which are easier to use in that the force needed to close the blades completely is not greatly increased over that required to close the blades partially during a cutting stroke of the scissors.
What is needed, then, is an improved multi-purpose folding tool including folding scissors which are easily used, which provides ample leverage through handles of adequate length, which are easily stowed within the handle of the multi-purpose folding tool, and which do not interfere with the utility of other folding tool bits included in the multi-purpose folding tool. It is also desired for such folding scissors to be larger than previously available folding scissors included in a multi-purpose folding tool of a comparable size, and that the entire tool in a folded configuration can be easily carried in a person""s pocket without causing unnecessary wear of the fabric of the pocket.
The present invention provides a multi-purpose folding tool which overcomes the previously-mentioned shortcomings and disadvantages of previously known folding tools by providing improved folding scissors and other tools having pivotally interconnected jaws or the like.
In one embodiment of the present invention a channel-shaped folding handle is attached to each of a pair of interconnected movable members such as the blades of a pair of scissors and a pair of springs in each handle operate, respectively, on the attached member such as a scissors blade and an adjacent rocker. Both springs in each handle operate to hold the handles together with the multi-purpose tool in a folded configuration. With the scissors, for example, ready for use, one spring in each handle holds the attached scissors blade securely aligned with the handle, while the other spring operates the associated rocker to urge the scissors blades toward an open position after each cutting stroke. Each rocker is linked with the adjacent scissors blade so that the rocker is free to pivot through a small angle relative to the blade but is moved along with the blade between the stowed position and the deployed position of the blade.
In a preferred embodiment of the invention, additional folding tool bits are included in the handles, mounted on tool pivot shafts spaced apart in the handles from the location of the scissors blades. When such tool bits are used, the handles are prevented from moving laterally with respect to each other by an ear on one of the springs in each handle and by a portion of each rocker extending alongside the scissors blade associated with the other handle.
In one embodiment of the invention a lanyard-attachment ear mounted on a pivot shaft may be extended for use or folded into a stored position where it is not likely to wear the fabric of a pocket in which the tool is carried.
In another preferred embodiment of the invention a pair of folding scissors is movable around a pivot shaft, between a stowed position in a handle of a multi-purpose folding tool and a deployed position in which the folding scissors extends with a first scissors blade held in a fixed position with respect to the handle of the multi-purpose tool. A second scissors blade is pivoted with respect to the first, while an operating lever is pivoted with respect to both of the blades and can engage the movable blade to move the blades toward a closed position in a cutting stroke of the scissors.
A rocker is mounted to pivot about the same shaft on which the main scissors blade is mounted and is pushed by a leaf spring also used to hold a selected one of the several tool bits of the multi-purpose tool. The rocker includes an outer end which pushes against a base portion of the movable second scissors blade to urge the blades toward an open position during use of the scissors. A single spring included in the handle of the multi-purpose tool thus operates to hold the main blade in position with respect to the handle and also to operate the rocker which moves the second scissors blade toward an open position during operation of the scissors according to the invention.
In one embodiment of the invention the operating lever nests alongside the scissors blades in the stowed position of the folding scissors, but is easily lifted into a position in which a portion of its base operates as a cam to move the scissors from their stowed position toward the deployed position.
In another embodiment of the invention, adjacent blades are engaged by tapered tips of adjacent springs each engaging only a particular one of the adjacent blades.
In other embodiments of the invention, pliers or other tools may include jaws or jawlike members pivotally interconnected with each other and arranged to be folded and stowed in tool handles in a manner similar to that in which the scissors blades operate and are interrelated with the tool handles.